1. Gordon PH, Nivatvongs S. Principles and Practice of Surgery for the Colon, Rectum, and Anus. Second Edition. Quality Medical Publishing, Inc. St. Louis, Missouri. 1999;10:242-286.
2. Shelygin Yu.A., Blagodarny L.A. Spravochnik po koloproktologii. Geotar-Media, 2014; 608 p. (in Russ.).
3. Sugrue J, Nordenstam J. Pathogenesis and persistence of cryptoglandular anal fistula: a systematic review. Tech Coloproctol. 2017;21(6):425-432. DOI: 10.1007/s.10151-017-1645-5.
4. Herold A. et al. Coloproctology, European Manual of Medicine. Springer, 2017;59-74.
5. Dultsev Yu.V., Salamov K.N. Paraproctitis. М., 1981. 208 p. (in Russ.).